Ribociclib and Letrozole Treatment in Ovarian Cancer

The study evaluates the response to treatment with Ribociclib and Letrozole in patients with low grade serous cancer of the ovary, fallopian tube or peritoneum.

Ribociclib (formerly LEE011) is an orally bioavailable, highly selective small molecule inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6). Ribociclib has been approved by the United States Food and Drug Administration (U.S. FDA) and the European Commission as an initial endocrine-based therapy for the treatment of postmenopausal women with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer in combination with an aromatase inhibitor based on a randomized, double-blind, placebo-controlled, international clinical trial (MONALEESA-2). Additional marketing authorizations are under review by health authorities. Additional phase III clinical trials for the treatment of hormone receptor positive (HR+) breast cancer patients, as well as several other phase I or II clinical studies are being conducted. Letrozole is a highly potent, orally active non-steroidal competitive inhibitor of the aromatase enzyme system. It effectively inhibits the conversion of androgens to estrogens both in vitro and in vivo. It is indicated both as first-line treatment of postmenopausal women with hormone receptor positive or hormone receptor unknown locally advanced or metastatic breast cancer as well as for the treatment of advanced breast cancer in postmenopausal women with disease progression following antiestrogen therapy. Based on encouraging results in women with advanced hormone-receptor-positive breast cancer, a clinical trial for women with recurrent low-grade serous carcinoma is warranted. Furthermore, such a trial would have great appeal to women with recurrent low-grade serous carcinoma, a cohort with limited therapeutic options. Although low-grade serous carcinoma is a rather uncommon histologic subtype, prolonged overall survival results in a relatively high prevalence.